Using the transcript at the New York Times, here is a breakdown showing how many words were spoken in each topic area (by both the moderators and Clinton and Obama) at the Democratic debate in Philadelphia:

Red is for generic politics (delegates, running mates).

Yellow is for the "gotcha" items (and includes asking candidate X if "Y can win").

Green is foreign policy.

Blue is taxes (including remarks that Hillary made that strayed from the CapGains tax questions) and gas/oil.

Pale blue for guns

White for Affirmative Action

Of the (approximately) 15,649 words spoken, 5,811 - or 37% - were devoted to the "gotcha" category.

On economic issues, the ABC moderators focused on taxes and ignored the national debt and any mention of spending for a safety net (as we head into a recession).